Featured Research

from universities, journals, and other organizations

A New State Of Matter Turns A Solid World Into A Melting One

Date:

September 14, 1997

Source:

University Of Washington

Summary:

A new form of matter, clusters of atoms, has been oberved in recent years behaving in curious ways. Now research indicates that clusters have another, previously unsuspected property: they can melt at different temperatures from "solid" matter.

Share This

A new form of matter, clusters of atoms, has been oberved in recent years behaving in curious ways. Now research indicates that clusters have another, previously unsuspected property: they can melt at different temperatures from "solid" matter.

Related Articles

An experiment described in last week's Science (Sept. 12) paints an exotic portrait of certain substances seemingly confounding nature by existing as a liquid, instead of a solid, at room temperature.

George Bertsch, a theoretical physicist at the University of Washington, describes how the experiment with clusters of sodium atoms found that the atoms did not follow sodium's normal pattern, melting at 97.8 degrees Centigrade (208 degrees Fahrenheit). Instead, the small clusters of atoms melted at minus 6 degrees Centigrade (21 degrees Fahrenheit), well below room temperature.

The discovery was the work of Hellmut Haberland at the University of Freiburg in Germany. Bertsch, who has been following the field of cluster research for the past decade, writes that as a result of the experiment, scientists are now challenged "to understand what happens to the liquid and solid phases in small particles."

European researchers are working on a number of practical applications for the cluster phenomenon. Attempts are being made to produce thin films of silicon clusters that would process signals carried by light. Others are researching the use of clusters to improve the magnetic recording of data. And Haberland has been reported to have produced clusters of the element molybdenum that will even stick to Teflon.

Clusters have been called a new type of matter, says Bertsch, because they appear to be a bridge between atoms and the world of normal size, and have strange magnetic, electrical and optical properties. What is particularly curious, he says, is that the properties of the clusters depend on the number of atoms they contain.

Bertsch notes that most clusters are very unstable collections -- "they touch a wall and they are gone." But a decade ago it was discovered that certain clusters contain "magic numbers" of atoms that make them particularly stable. These numbers begin with just two atoms, and continue through eight, 20 and 40 and into the hundreds of atoms.

The German researcher used magic-number clusters of 139 sodium atoms. The melting point was observed by forming condensation 'droplets', rather like hot steam hitting a cold window, and passing the condensate through a mass spectrometer and finally an electric field.

Bertsch concedes that the research is controversial, and there are physicists who insist there can only be one melting temperature for each of the 92 natural elements. But, he says, "as scientists we have to look at the evidence." What's more, he believes there is evidence that the same phenomenon that the German researcher demonstrated with sodium, also exists with atomic clusters of both tin and lead.

The UW scientist is hesitant to attempt an explanation of what is causing the lower melting point of these elements. However, he notes, it has been suggested that there is a relation to a theory known as surface melting: when a substance reaches melting temperature, only a small surface layer melts immediately. "As solid sodium reaches melting temperature, a small layer of liquid might form on top of the solid," he says. "In a cluster, all you would have is this outer, liquid layer."

It could be said, says Bertsch, that this new type of matter is "practically all surface." If there is already something strange happening at the surface of certain elements, "then you accentuate that behavior when you create clusters."

Story Source:

The above story is based on materials provided by University Of Washington. Note: Materials may be edited for content and length.

University Of Washington. "A New State Of Matter Turns A Solid World Into A Melting One." ScienceDaily. ScienceDaily, 14 September 1997. <www.sciencedaily.com/releases/1997/09/970914234606.htm>.

University Of Washington. (1997, September 14). A New State Of Matter Turns A Solid World Into A Melting One. ScienceDaily. Retrieved March 3, 2015 from www.sciencedaily.com/releases/1997/09/970914234606.htm

University Of Washington. "A New State Of Matter Turns A Solid World Into A Melting One." ScienceDaily. www.sciencedaily.com/releases/1997/09/970914234606.htm (accessed March 3, 2015).

More From ScienceDaily

More Matter & Energy News

Featured Research

Mar. 3, 2015 — By examining the forces that the segments of mosquito legs generate against a water surface, researchers have unraveled the mechanical logic that allows the mosquitoes to walk on water, which may ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — Major cities in the UK are falling behind their international counterparts in terms of their use of smart technologies, according to a new study. The research has found that smart cities in the UK, ... full story

Mar. 3, 2015 — Scientists have explored friction at the microscopic level. They discovered that the force generating friction is much stronger than previously thought. The discovery is an important step toward ... full story

Mar. 3, 2015 — Micro-drones are already being put to use in a large number of areas: These small aircraft face extensive requirements when performing aerial observation tasks or when deployed in the field of ... full story

Mar. 3, 2015 — Recent research contributes to the effort to determine the nature of dark matter, one of the most important mysteries in physics. As indirect evidence provided by its gravitational effects, dark ... full story

Mar. 3, 2015 — Physicists have shown for the first time that electrons in graphene can be moved along a predefined path. This movement occurs entirely without loss and could provide a basis for numerous ... full story

Featured Videos

Forensic Holodeck Creates 3D Crime Scenes

Reuters - Innovations Video Online (Mar. 3, 2015) — A holodeck is no longer the preserve of TV sci-fi classic Star Trek, thanks to researchers from the Institute of Forensic Medicine Zurich, who have created what they say is the first system in the world to visualise the 3D data of forensic scans. Jim Drury saw it in operation.
Video provided by Reuters

Solar Plane Passes New Test Ahead of World Tour

AFP (Mar. 2, 2015) — A solar-powered plane made a third successful test flight in the United Arab Emirates on Monday ahead of a planned round-the-world tour to promote alternative energy. Duration: 01:05
Video provided by AFP

Electric Hydrofoiling Watercraft Delivers Eco-Friendly Thrills

Reuters - Innovations Video Online (Mar. 2, 2015) — The Quadrofoil is a high-tech electric personal watercraft that its makers call a &apos;sports car for the water&apos;. When it hits 10 km/h, the Slovenian-engineered Quadrofoil is lifted above the water onto four wing-like hydrofoils where it &apos;flies&apos; above the surface with minimal water resistance. Matthew Stock reports.
Video provided by Reuters

Related Stories

Nov. 6, 2014 — The seemingly simple process of phase changes -- those transitions between states of matter -- is more complex than previously known. New work reveals the need to rethink one of science's ... full story

Feb. 26, 2014 — Astrophysicists may have identified a trace of dark matter that could signify a new particle: the sterile neutrino. Another research group reported a very similar signal just a few days ... full story

May 1, 2010 — Physicists have succeeded in isolating for the first time a sample of spin polarized positronium atoms, needed to make the Bose-Einstein condensate. The researchers say they have effectively purified ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.